Field of the Invention
The present invention relates to a touch detecting apparatus and a touch detecting method using a pixel or pixels in display devices.
Discussion of the Background
Generally, a touch screen is an input device that is added on display devices such as a liquid crystal display (LCD), a plasma display panel (PDP), an organic light emitting diode (OLED), and an active matrix organic light emitting diode (AMOLED) or designed to be embedded in the display devices and is a device that recognizes objects such as a finger and a touch pen as an input signal when the objects contact the screen. In recent years, a touch input device has been mostly mounted in mobile devices such as a mobile phone and personal digital assistants (PDA). In addition, the touch input device has been used for the whole industrial fields such as, navigation, a netbook, a notebook, a digital information device, a desk top computer using a touch input support operating system, an internet protocol TV (IPTV), a cutting edge fighter, a tank, and an armored car.
The touch screen used for the foregoing display device, or the like may be divided into an add-on type touch screen, an on-cell type or in-cell type touch screen depending on a structure thereof. The add-on type touch screen is a type that adds individually manufactured touch screens on an upper plate of a display device and has a problem in that since a manufacturing subject of the display device and a manufacturing subject of the add-on type touch screen are different, a distribution is complicated and thus quality is low and costs rise.
On the other hand, the on-cell type or in-cell type touch screen is a type of manufacturing a touch screen simultaneously with manufacturing a display device and there are an on-cell type touch screen in which a touch screen is installed outside a display device such as a color filter of a display device and a TFT substrate and the in-cell type touch screen in which a touch screen is embedded in a display device.
The on-cell type or in-cell type touch screen may improve durability and be slimmed during a manufacturing process and therefore may solve problems that occur in the add-on type touch screen in which the touch screen is added on the upper plate of the display device.
However, to manufacture the on-cell or in-cell type touch screen, a touch sensor detecting a touch signal needs to be separately manufactured on an outer side or an inner layer of the display device, and therefore there is a problem in that productivity is reduced at the time of manufacturing the on-cell or in-cell type touch screen by additionally progressing facility investment or using the existing facilities in the existing display device manufacturers.